Unit 4.3: Respiratory and Cardiovascular Care

• Topic 01

  Oxygen Therapy

  45 questions
• Topic 02

  Airway Management

  45 questions
• Topic 03

  ECG Recognition

  45 questions
• Topic 04

  Venepuncture, Cannulation, and IV Therapy Management

  45 questions

A few questions from this unit, with the answer and a full explanation. The complete bank is available when you start practising.

1. A Trust audit finds that IV catheter-related bloodstream infections (CRBSIs) have increased. A root cause analysis suggests that nurses are applying correct skin antisepsis but frequently touching key parts during the procedure. The infection control team asks the nurse educator to reinforce a specific principle. Which ANTT principle is MOST directly relevant?

   • A
     The principle that key parts must never be touched regardless of glove use; touching key parts — even with sterile gloves — undermines ANTT and is the most common cause of ANTT failure leading to CRBSI
     Correct answer
   • B
     The principle that skin antisepsis must be performed for a minimum of 30 seconds using 2% chlorhexidine in 70% IPA
   • C
     The principle that all ANTT procedures must use sterile gloves rather than non-sterile gloves
   • D
     The principle that hand hygiene must be performed using alcohol gel rather than soap and water before all IV procedures
   Explanation

   The audit finding that nurses are touching key parts despite correct skin antisepsis identifies a failure of the central ANTT principle: key parts must never be touched. Skin antisepsis (key site protection) is only one aspect of ANTT. If key parts (needle tips, cannula hubs, syringe tips) are contaminated by touch — even with gloved hands — the aseptic technique has been broken and the risk of CRBSI increases regardless of how good the skin preparation was. The educator must reinforce that no-touch protection of key parts is non-negotiable and applies throughout the procedure, not just during insertion.

2. A student nurse asks why blood cultures must always be collected first in the order of draw when they are required. Which explanation is MOST accurate?

   • A
     Blood cultures must be collected last to avoid contaminating other tubes with the anticoagulant in the culture bottles
   • B
     Blood cultures are always collected by a doctor, not a nurse, so order of draw does not apply to them
   • C
     Blood cultures must be collected first to minimise the risk of contamination from skin bacteria; collecting them first ensures the sample is taken at the point of initial venepuncture when skin contamination risk is lowest, and before any tube additives could interfere with culture results
     Correct answer
   • D
     Blood cultures are not required to follow order of draw rules as they use a separate collection system
   Explanation

   Blood cultures are collected first to minimise contamination from two sources: (1) skin bacteria — the risk of introducing skin flora into the culture bottles is highest at initial needle entry when the needle track through the skin is freshest; subsequent tubes pass through the same puncture site, reducing additional contamination risk; (2) additive contamination — collecting cultures before other tubes ensures no additive from other tubes can carry over into the culture bottles and interfere with bacterial growth. Collecting cultures last risks both skin flora contamination (from re-puncture debris) and additive interference.

3. A nurse is explaining the cardiac conduction system to a student. The student asks why each heartbeat is preceded by a P wave when the impulse originates in the SA node. What is the BEST explanation?

   • A
     The P wave represents atrial repolarisation, which occurs before ventricular depolarisation begins
   • B
     The SA node generates an impulse that spreads across both atria, depolarising atrial muscle cells; this depolarisation produces the P wave on the ECG before it reaches the AV node and then the ventricles
     Correct answer
   • C
     The SA node sends an impulse directly to the ventricles which produces the P wave as a side effect
   • D
     The P wave is produced as the impulse travels through the Bundle of His before reaching the ventricles
   Explanation

   The SA node generates an electrical impulse that spreads radially across the atrial myocardium through specialised conduction pathways. As this wave of depolarisation passes through atrial muscle cells, it produces the P wave on the ECG. This occurs before the impulse reaches the AV node (where it is delayed), the Bundle of His, bundle branches, and Purkinje fibres. The P wave therefore confirms that each heartbeat begins with SA node-initiated atrial depolarisation — the defining feature of a sinus rhythm.